Figure 9.

Real (red dashed line) and imaginary (blue solid line) parts of dielectric function in NiH${}_{0.25}$ calculated at q = 0.032 Å${}^{-1}$ pointing in [110] symmetry direction and respective loss function, −Im$\left[{ϵ}^{-1}\right]$, (black solid line). Features in Im$\left[ϵ\right]$ generated by the states marked in the DOS of Figure 7e,f are labeled by respective symbols. The energy regions where Re$\left[ϵ\right]$ approaches the zero line are marked by gray arrows. Features in the loss function corresponding to strongly damped acoustic plasmon modes are denoted as SAP${}_1$ and SAP${}_2$.